Given the high electrical conductivity of copper and copper alloys and their low resistance, copper parts are practically impossible to weld with resistance, unless technical measures are taken.
The main measure is to transfer the contact resistance, using resistance welding electrodes with refractory material (Tungsten or Molybdenum).
In this way the increased resistance, due to the contact of these high strength refractory materials, is transferred from the contact of the internal surfaces of the workpieces to the contact between the electrode tips and the external surfaces of the workpieces.
The heat transfer will therefore take place from the outside to the inside, with the consequence that the molten core, compared to that of ferrous metals, will have a smaller diameter but a greater thickness with a more marked dimpling of the electrode.
A.T.S. is a qualified supplier of the main resistance welding electrodes in copper alloy with Tungsten or Molybdenum insert.